LAN segmentation with routers / LAN segmentation with switches

LAN segmentation with routers
4.2.3 Routers provide network segmentation which adds a latency factor of twenty to thirty percent over a switched network. The increased latency is because routers operate at the network layer and use the IP address to determine the best path to the destination node. Figure

shows a Cisco router.
Bridges and switches provide segmentation within a single network or subnetwork. Routers provide connectivity between networks and subnetworks.
Routers do not forward broadcasts while switches and bridges must forward broadcast frames.

The Interactive Media Activities will help students become more familiar with the Cisco 2621 and 3640 routers.
The next page will discuss switches.

LAN segmentation with switches

4.2.4 Switches decrease bandwidth shortages and network bottlenecks, such as those between several workstations and a remote file server. Figure

shows a Cisco switch. Switches segment LANs into microsegments which decreases the size of collision domains. However, all hosts connected to a switch are still in the same broadcast domain.

In a completely switched Ethernet LAN, the source and destination nodes function as if they are the only nodes on the network. When these two nodes establish a link, or virtual circuit, they have access to the maximum available bandwidth. These links provide significantly more throughput than Ethernet LANs connected by bridges or hubs.

This virtual network circuit is established within the switch and exists only when the nodes need to communicate.
The next page will explain the role of a switch in a LAN.

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